Mangrove ecosystems harbor diverse bacterial communities that significantly affect soil properties. Among these bacteria are cellulolytic species, which contribute to the breakdown of organic matter. This study aimed to analyze the total population of cellulolytic bacteria and their relationship with soil characteristics in mangrove ecosystems along the coast of Banda Aceh and Aceh Besar, Aceh Province, Indonesia. Six research locations were selected, with soil samples taken at three depth intervals: 0-15 cm (Layer 1), 15-30 cm (Layer 2), and 30-45 cm (Layer 3). The total population of cellulolytic bacteria was found to vary depending on both sampling location and soil depth. The highest total population of bacterial colonies was observed at location 2.3. However, on average, the soil surface (Layer 1) harbored a higher number of cellulolytic bacteria (13.0×10 7 CFU g -1 dry soil) compared to Layers 2 and 3 (5.0×10 7 and 8.0×10 7 CFU g -1 dry soil, respectively). A significant correlation was observed between the total bacterial population and organic carbon content (P < 0.05), while no significant correlations were found with soil particle size, pH, salinity, total nitrogen, available phosphorus, or soil moisture (P > 0.05). Unrehabilitated mangrove ecosystems exhibited higher levels of cellulolytic bacterial populations, sand and silt fractions, pH, salinity, organic carbon, total nitrogen, and moisture compared to rehabilitated mangrove ecosystems.